1. Field of the Invention
This invention relates to a jack for returning the wheels of a derailed rail car to the track and, more particularly, to a re-railing jack adaptable for removable connection and pivotal movement in the receiver for the coupling of the rail car.
2. Description of the Prior Art
Lifting jacks, as disclosed in U.S. Pat. No. 1,088,236, are known for replacing a derailed rail car upon a track. The lifting operation requires vertically raising the wheels of the rail car above the upper level of the track and then laterally moving and simultaneously permitting the car to fall in a downward arc about the base of the jack onto the track. The above referenced patent discloses a bearing secured to the underside of the rail car adjacent and separate from the rail car coupler. The bearing receives a support for a lifting screw in which the support and the lifting screw are pivotally supported by the bearing. The upper end of the lifting screw is slidably connected to the upper edge of the car body, and the lower end is provided with a swivel base. A hand operated ratchet is provided for rotating the screw in either direction to raise and lower the car.
U.S. Pat. No. 1,062,871 discloses a lifting jack which is movable along the track. The lifting jack is connected to the car body in a manner to permit the jack to be swung about a horizontal axis into and out of an operative position. In this manner, the jack is carried on the rail car in a position where it is entirely out of the way when not in use. U.S. Pat. Nos. 862,609; 981,617; 1,099,405 and 1,107,706 also disclose lifting jacks movable into and out of position for re-railing a derailed rail car or for transferring a rail car from one set of tracks to another.
Lifting jacks, which are not connected to the rail car which is lifted and moved into position on the track, are considered hazardous to operating personnel because of the tendency for the jack to be displaced and fly out in a random direction when the vehicle is moved laterally and downwardly with the jack extended. Even though the lifting jacks which are not connected to the car body are provided with swivel bases in most cases, when the vehicle has to move laterally at an angle for a considerable distance, the base has a tendency to shift and move out of contact with the ground resulting in a sudden downward, uncontrolled movement of the vehicle which can result in serious bodily injury to operating personnel.
While the above-described lifting devices, which are attached to the vehicle, have attempted to solve the problem of uncontrolled shifting movement of the jack and prevent resultant injury which may occur, major modifications are required to the jack and the vehicle so that the jack can be connected to the vehicle in a manner to be easily moved to an out-of-way position on the vehicle. Due to the expense and lack of versatility of lifting jacks which are permanently secured to vehicles, they have not been generally accepted for use on rail vehicles operated either above or below ground, as for example on locomotives and rail cars used in underground mining operations. Furthermore, permanently securing a lifting jack to a vehicle limits that lifting jack to that specific vehicle, thereby requiring every vehicle to have a lifting jack. This constitutes a substantial expenditure to the operator. Consequently, the separate jacks which are known to be inherently dangerous are still being commonly used, particularly with underground track equipment.
There is a need for a jack for lifting a derailed vehicle upon a track where the jack is removably secured to the vehicle to be lifted in a manner which prevents the jack from flying out in a random direction and can be easily connected and disconnected from the vehicle without requiring major modifications to be made to the vehicle or requiring detailed construction of the jack. While it has been suggested to provide lifting jacks which are either removably connected to the vehicle or are connected to the vehicle for movement into and out of an operative position, the prior art lifting jacks require either that the jack be permanently secured to the vehicle or the vehicle by extensively modified to receive the jack in a manner that it can be connected and disconnected to the vehicle.